Electrical chargers and other power supplies are commonly used for charging batteries and providing power to various electronic devices. In cases where the electrical charger, power adapter, or other power supply is not in use or only a portion of the cable is required, retractable cable assemblies may be used to retract and wind the unused cable around a spool contained within an enclosed compartment. Electrical chargers and other devices with cords with retractable cable assemblies have been presented in the prior art; however, those devices are not ergonomic and include disadvantages that have not been overcome.
For example, manual retraction mechanisms have been used wherein a user may manually wind the cable using a handle attached to a spool in order to retract the cable, such as those shown in U.S. Pat. No. 6,540,168 and U.S. Patent App. 2004/0256188. This method is undesirable as it could be cumbersome for the user to manually retract the cable, particularly if the cable is long. Apart from manual retraction of the cable, several proposed retractable cable assemblies rely on the use of a torsional spring to automatically retract the cable. In these cases, the torsional spring is rotatably coupled to the spool. As the cable is pulled and unwound from the spool, the spool and the coupled torsional spring rotate. As the torsional spring rotates it compresses such that elastic energy is stored within the spring. A lock-release system is used to hold the coupled spring and spool in place when the cord is extracted and in use. When the rotatably coupled spring and spool are released for retraction, the elastic energy stored in the spring acts to decompress the spring, causing it to rotate back to its original uncompressed state while at the same time rotating the coupled spool which then retracts the cable.
Different lock-release systems have been used with the torsional spring system. For example, a release method wherein pulling the cable a small distance outward triggers the release of the locking mechanism allowing the cable to retract, such as those shown in U.S. Pat. Nos. 7,364,109 and 3,705,962. This mechanism is disadvantageous as accidental triggering of the release mechanism can easily occur, resulting in unwanted retraction. In other cases, cord clamping, such as that shown in U.S. Pat. Nos. 6,230,860 and 6,616,080 or pawl-ratchet mechanisms as in U.S. Pat. Nos. 7,017,846, 6,578,683 and 6,803,525 have been used. For pawl-ratchet mechanisms, the extracted cord is held in place when the pawl is engaged with the ratchet. When the pawl is disengaged from the ratchet, the spool and the rotatably coupled compressed spring are released. The spool then rotates and retracts the cord as the released spring decompresses back to its original uncompressed state. A small button or latch coupled to a tension spring must often be depressed or pulled such that the tension spring is stretched enough to disengage the pawl. In cases where the spring is stiff, depressing or pulling of the tension spring is difficult and uncomfortable as significant force must be applied, often with a single finger, during retraction of the cord. With all of the described retractable cable mechanisms, continuous and excess pressure on the button or latch of a pawl-ratchet assembly or pulling of the cord to trigger release of the locking mechanism may also cause malfunctioning of the retractable cable mechanism over time.
The present invention includes a retractable cable assembly using a pawl-ratchet lock-release mechanism that overcomes the disadvantages of prior retractable cable assemblies. Other types of lock-release mechanisms such as a button or latch coupled to a locking member preventing the rotation of the spool or a switch wired to an electric motor controlling the rotation of the spool may be used in the cable assembly. Unlike retractable cable assemblies known in the art, the pawl is disengaged from the ratchet or any latch-, button- or switch-activated locking mechanism is released by rotation or twisting of the housing lid or the main housing body itself as opposed to depression or pulling of a button or latch or pulling of the electric cord. In this way, the user may comfortably apply the required rotational force to the cable assembly in order to keep the pawl disengaged during cable retraction and is not required to apply unnecessary force on the cable itself, providing for greater longevity and more frequent use of the retractable cable assembly. The novel invention described herein also provides an ergonomic design that allows for retraction of cables with greater ease and comfort over retractable cable assemblies known in the art. The invention described herein is versatile and may be adapted for use with any type of electronic device that requires a power supply.